Printing machines



June 21, 1966 J. KARRENBAUER PRINTING MACHINES Filed Aug. 15, 1963 FIG.3.

' INVENTOR JOSEF' KARRENBAUER Marya n, Ffmgzm, fla im ATTORNEYS United States Patent 3,256,812 PRINTING MACHINES Josef Karrenbauer, Darmstadt, Germany, assignor to Maschinenfabrik Goebel G.m.b.H., a company of Germany Filed Aug. 13, 1963, Ser. No. 301,762 Claims priority, application Germany, Aug. 16, 1962, M 53,901 Claims. (Cl. 101216) This invention relates generally to printing machines and relates more particularly to novel and improved bearin-g means for mounting impressing and printing cylinders.

Bearer rings are sometimes fitted to the shafts of the impression and printing cylinders of printing machines, the diameter of these rings being such, in relation to that of the cylinders, that the bearer ring of one cylinder rotates in contact with the bearer ring of the other cylidenr when printing is in progress. Such bearer rings serve several purposes. For example, when a flexible printing plate is fitted about a printing cylinder, a somewhat large gap is left between the edges of this plate on the cylinder, the surface in the gap lying below that-of the plate. As a result of this, every time the gap passes the impression cylinder in course of printing, there is a jolt which affects the entire machine. These continual shocks during printing are taken up and rendered harmless by the bearer rings as these run in contact with one another.

Bearer rings also have the advantage, when resilient printing plates are being used, of regulating the spacing between the printing and impression cylinders, so that even when the pressure is excessive, the printing plate is not crushed so as to give an unclear impression. Finally, bearer rings also even the running of the impression and printing cylinders when these are not of precisely the same diameter.

It has been found that with printing machines that require very heavy pressure between the impression and printing cylindersfor example, machines for printing from steel engravings-the bearer rings used hitherto are inadequate. This applies particularly to printing machines in which there is a gap of the kind already mentioned on one of the two cylinders. The surface pressure at the line of contact on the bearer rings then becomes so great that this portion ofthe rings soon deteriorates.

It is true that conical bearer rings exist in which the spacing of the impression and printing cylinders can be regulated by moving one bearer ring axially in relation to thebearer ring with which it is in contact as it rotates. This adjustment can be made only while the machine is at a standstill however, and this wastes a lot of time, because the print needs to be checked after every readjustment, which requires stopping the machine a number of times until the proper result is obtained. Moreover, bearer rings of this kind are also subject to the disadvantage of premature destruction already mentioned.

It is an object of the present invention to overcome the foregoing inadequacy of presently available printing press mechanism. Another object of the invention is to provide a novel and improved means for mounting the impression and printing cylinders of a printing machine which avoids an impact when the printing plate edge passes the impression cylinder. A further object of the invention is to provide a novel and improved means for mounting impression and printing cylinders which is capable of withstanding heavy pressures between the two cylinders and which does not permit a release of pressure between the cylinder surfaces when the printing plate gap passes over the surface of the impression cylinder. Another object of the invention is to provide 'a novel mounting means which permits impact-free operation of a print- 3,256,812 Patented June 21, 1966 ing machine and which at the same time enables the spacing of the impression and printing cylinders to be regulated during the run.

The foregoing objects are derived from the embodiments of the invention herein illustrated, wherein each of the impression and printing cylinders are rotatably mounted in two sets of roller bearings, spaced coaxially at each end of each of the shafts thereof. Each'set of bearings runs in a separate non-rotatable housing, the inner set of bearings running in oppositely disposed housings having adjustable means fitted therebetween so as to vary the spacing between the housings and, consequently, the pressure exerted between the impression and printing cylinders. Thus, the inner set of roller bearings may be said to constitute bearer rings, while the outer lengthwise, the distance between the housings will bevaried and, consequently the spacing between the impression and printing cylinders.

The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which: FIGURE 1 is a cross-sectional through the bearings of the bearings of the bearer rings of the various cylinders; FIGURE 2 is a side elevation of the bearer ring housings, and

FIGURE 3 is a side elevation partly in section showing screws with right-hand and left-hand threads, whichscrew into the housings and can be turned to alter the spacings between the housings.

The shaft 1 of printing cylinder 2 is mounted to rotate in bearings 3 and 4 in the stationary frame housings 5' and 6. The printing cylinder may be covered at its periphery with a flexible printing plate (not shown). The shaft 7 of impression cylinder 8 is similarly mounted in bearings 9 and 10 in bearing housing members 11 and 12, but these bearing members can move to the extent that pressure can be exerted on the shaft 7 in the direction of the arrows and the impression cylinder rendered operative and inoperative.

On portions of shaft 1 which are of reduced diameter are mounted bearer rings, which at the same time constitute the inner races of ball bearings 13 and 14. The outer races of these' bearings are secured in the stationary,

non-rotatable housings 15 and 16 respectively. On shaft 1 is also mounted a gear wheel 17, in mesh with gear wheel 18, secured on shaft 7. The gear wheels 17, 18, one of which may be driven by a further gear wheel (not shown), drive the impression and printing one and the same speed.

0n reduced portions of shaft 7 similarly are bearer cylinders at rings which constitute the inner races of the ball bearings 19 and 20, the outer races of which are retained in the non-rotatable housings 21 and 22.

Between the two housings at each end of each of the shafts 1 and 7, adjustable means are provided to vary the spacing between the cylinders.

printing. With nonadjustable bearer rings, the covering would have to be either prematurely renewed or packed underneath, to restore the quality of the impression.

As preferably embodied, this means comprises tapered Adjustment in this respect -1s necesary, for example, when the covering on the impression cylinder has been rolled thin in the course of members 23 and 24, each held in position by a screw 25,

the thread of which passes through a threaded hole in the tapered member, the screws being secured in one of the two housings in such a way that it can turn but cannot move axially. When the screw is turned by rotation of the handwheel 26, the appropriate tapered rnember- 23 or 24--is moved lengthwise. Since the housings are being pressed towards each other by the forces acting in the direction of the arrows, they follow the motion of the tapered surfaces and their distance apart is thereby altered. These alterations in spacing, acting through the ball bearings 13 and 19 of the bearer rings at one end, and 14 and 20 of the bearer rings at the other, bring about a similar alteration in the spacing of the shafts 1 and 7 and of the corresponding cylinders. In the course of this action, the positions of the housings 15 and 16 remain unchanged, shaft 1 being so mounted as to remain stationary, whereas the housings 21 and 22 and the impression cylinder 8 move through a distance determined by the displacement of the tapered members.

The housings 15, 16, 21 and 22 need not be secured because they are retained peripherally by their ball bearings, and they cannot rotate because they bear against each other along one flat surface.

Alternatively, instead of the tapered members 23 and 24, screws, as illustrated in FIGURE 3, may be used, which are screwed into corresponding recesses in housing 21 and which bear against similar recesses in housing 15. By turning the screws, the distance between housings 15 and 21 may be enlarged or reduced as when operating by displacement of the tapered members. The displacement between the housings 16 and 22 is also effected in this manner.

With reference to the foregoing description and drawings, the operation of a printing machine having the impression and printing cylinders mounted in a pair of roller bearings at each end of each of the shafts thereof is as follows:

The force required for printing acts on the bearing housing 11 in the direction of the upper arrow and is transmitted from the housing over the roller bearing 9 onto the shaft 7. As the shaft 7 is fixedly connected to the cylinder 8, the latter is charged by part of this force which results in pressure being developed between the two cylinders. The pressure generated by the reaction force in the cylinder 2 acts on the shaft 1 so that the left-hand shaft 1 bears against the roller bearing 3 which is secured to the stationary 'frame housing 5.

A further part of the force exerted on the housing 11 progresses over the shaft 7, the roller bearing 19, the housing 21, the tapered member 23 and the housing 15, the roller bearing 13, the shaft 1 and also over the roller bearing 3 and is taken up by the stationary frame housing 5. The distribution of force through both the cylinders and the shafts is only effected if the printing form passes the printing cylinder 2 on the impression cylinder 8. If however the gap of the form is positioned opposite the impression cylinder 8, no pressure is transmitted between the two cylinders and the force than progresses only through the bearings on the shafts.

Thus, it will be understood that the shafts 1 and 7 (and of course also the shaft at the right-hand side of the cylinder) cannot be moved towards each other, whether or. not the printing form or the gap passes the impression cylinder 8. The reciprocal distance of the two shafts and also of the two cylinders is thus exactly determined, namely, that distance between the two roller bearings 13 and 19, the sides in question of the housings 15 and 21 and also the tapering member 23. This results in the fact that even when passing the gap no oppositely directed movement of the two cylinders can occur. reason any impact is avoided, which is a primary object of the invention.

Where printing and impression cylinders are mounted in only one roller bearing on each side, clearance between For this the bearing and cylinder shaft is usually unavoidable. The provision of two rolling bearing means eliminates this clearance and serves to maintain the exact distance between the shafts and cylinders, which further serves to avoid impacts. Thus, when the roller bearing 9 is pressed down against the shaft 7, a possible clearance would then only occur beneath the shaft. This clearance, however, can have no effect as the shaft 7 presses with its lower side against the roller bearing 19. Likewise, the possible clearance of roller bearing 19 can only occur on the top side of shaft 7 but has no effect as the top side presses against roller bearing 9. The conditions with respect to the shaft 1 and the roller bearings 3 and 13 are similar. It will also be understood that in similar manner, possible clearance between the rollers and the bearing rings is also made inefiective. A slackness of the bearing is thus made completely ineffective in a printing machine constructed in accordance with the present invention.

I claim:

1. In a printing machine having an impression cylinder and a printing cylinder and wherein said cylinders are mounted in pairs on respective rotatable shafts, means for mounting said impression and printing cylinders capable of withstanding heavy pressures and .being adjustable during operation of the printing machine, said means comprising substantially rigid rolling bearing means oppositely disposed on each end of each of said shafts, each of said bearing means comprising a pair of roller bearing rings rotatably mounted in separate, non-rotatable housings, the housings on each end of the printing cylinder shaft being in opposed alignment with.

the housings on each end of the impression cylinder shaft and adjustable pressure means intermediate and in contact with the inner housing on each of said printing cylinder shaft and the oppositely disposed inner housing on each end of said printing cylinder shaft for adjusting the spacing between said cylinders during operation of;

pact-free operation, said means comprising substantially rigid rolling bearing means oppositely disposed on each end of each of said shafts, each of said bearing means comprising two sets of roller bearing rings rotatably mounted in separate non-rotatable housings, the housings on each end of the printing cylinder shaft being in opposed alignment with the housings on each end of the impression cylinder shaft and adjustable means at each end of said shafts intermediate and in contact with the non-rotatable, oppositely disposed housings of one of said sets of roller bearings for varying the spacing between said cylinders during operation of the printing machine.

3. A printing machine as claimed in claim 2, wherein said adjustable means comprises tapered means mounted between the non-rotatable, oppositely disposed housings of one of said sets of roller bearings, whereby movement of said tapered means in a first direction operates to move said housings in a second direction normal to said first direction.

4. A printing machine as claimed in claim 2 wherein said adjustable means comprises screw means, said screw means being mounted in one of the non-rotatable housings of one of said sets of roller bearings and bearing against the oppositely aligned non-rotatable housing thereof, whereby rotation of said screw means adjusts the distance between said housings. 4

5. In a printing machine having an impression cylinder and a printing cylinder and wherein said cylinders are mounted in pairs on respective rotatable shafts, means for mounting said impression and printing cylinders capable of impact-free operation under heavy pressures and being adjustable during operation of the printing machine, said means comprising substantially rigid rolling bearing means oppositely disposed on each end of each of said shafts, each of said bearing means comprising a pair of coaxially spaced roller bearing rings ro tatably mounted in separate non-rotatable housings, the housings on each end of the printing cylinder shaft being in opposed alignment with the housings on each end of the impression cylinder shaft, and adjustable pressure means intermediate and in contact with the inner housing on each end of said printing cylinder shaft and the oppositely disposed inner housing on each end of said impression cylinder shaft for adjusting the spacing between said cylinders during operation of the printing machine, whereby the pressure exerted between the impression and printing cylinders is maintained constant throughout the printing operation.

References Cited by the Examiner UNITED STATES PATENTS 2,079,001 5/1937 Crafts 101-247 2,362,069 11/1944 Huck 101216 2,405,795 8/1946 Luehrs 101-247 2,724,331 11/1955 Schmidt 101216 FOREIGN PATENTS 401,409 11/1933 Great Britain.

DAVID KLEIN, Primary Examiner.

EUGENE R. CAPOZIO, I. REED FISHER,

Assistant Examiners. I 

1. IN A PRINTING MACHINE HAVING AN IMPRESSION CYLINDER AND A PRINTING CYLINDER AND WHEREIN SAID CYLINDERS ARE MOUNTED IN PAIRS ON RESPECTIVE ROTATABLE SHAFTS, MEANS FOR MOUNTING SAID IMPRESSION AND PRINTING CYLINDERS CAPABLE OF WITHSTANDING HEAVY PRESSURES AND BEING ADJUSTABLE DURING OPERATION OF THE PRINTING MACHINE, SAID MEANS COMPRISING SUBSTANTIALLY RIGID ROLLING BEARING MEANS OPPOSITELY DISPOSED ON EACH END OF EACH OF SAID SHAFTS, EACH OF SAID BEARING MEANS COMPRISING A PAIR OF ROLLER BEARING RINGS ROTATABLY MOUNTED IN SEPARATE, NON-ROTATABLE HOUSINGS, THE HOUSINGS ON EACH END OF THE PRINTING CYLINDER SHAFT BEING IN OPPOSED ALIGNMENT WITH THE HOUSINGS ON EACH END OF THE IMPRESSION CYLINDER SHAFT AND ADJUSTABLE PRESSURE MEANS INTERMEDIATE AND IN CONTACT WITH THE INNER HOUSING ON EACH OF SAID PRINTING CYLINDER SHAFT AND THE OPPOSITELY DISPOSED INNER HOUSING ON EACH END OF SAID PRINTING CYLINDER SHAFT FOR ADJUSTING THE SPACING BETWEEN SAID CYLINDERS DURING OPERATION OF THE PRINTING MACHINE, SAID ADJUSTABLE PRESSURE MEANS COMPRISING TAPERED MEANS MOUNTED BETWEEN SAID INNER HOUSINGS, WHEREBY MOVEMENT OF SAID TAPERED MEANS IN A FIRST DIRECTION OPERATES TO MOVE SAID INNER HOUSINGS IN A SECOND DIRECTION NORMAL TO SAID FIRST DIRECTION. 